Cable regulator assemblies are used for controlling the movement of a windowpane, such as a vertically moveable side window of a motor vehicle. Especially in motor vehicle applications, in which the regulator assembly typically is installed in a door cavity below the window opening, the regulator assembly should not interfere with other components, for example, anti-intrusion beams and the like. The cable must be guided along a travel path, preferably being well protected against chaffing and dislocation over extended periods of use in harsh automotive conditions, including temperature and humidity cycles, vibration and perhaps intrusion of foreign objects. Various cable regulator assemblies are known, typically having a drive cable mounted onto one or more cable guides and driven by suitable drive means, for example, a drive drum mounted for reversible rotation by a hand crank, electric motor or the like. The drive cable is attached to one or more driven members, sometimes referred to as gliders, such that the position of the driven member can be controlled by actuating the drive means to controllably drive the cable. Exemplary cable window regulator assemblies for use in motor vehicles are shown in U.S. Pat. No. 4,910,917 to Bauer, entitled Bowden Cable Equipped Window Lift, and in earlier U.S. Pat. No. 4,110,935 to Sessa, entitled Cable-Actuated Car-Side-Window-Lifting Mechanism.
In cable regulator assemblies in which a single glider is used, it generally is rigidly, i.e. fixedly, attached to the windowpane. Nevertheless, single glider designs have been known to provide inadequate stability to the window, allowing it to rock or rotate in its lifting plane as the windowpane is being raised or lowered. It is known that improvement can be obtained by using a pair of gliders attached to the windowpane at spaced locations along its bottom edge. Both the aforesaid Sessa patent and Bauer patent show regulator assemblies employing dual mounting brackets. The advantages of dual guide rails for motor vehicle window regulators are recognized, for example, in commonly owned U.S. Pat. No. 5,398,449 to Kobrehel et al, entitled Window Regulator for a Frameless Door Assembly.
Significant difficulties have been experienced, however, using cable regulator assemblies having such dual mounting brackets or gliders if the brackets are not lifted and lowered along precisely parallel paths. The Bauer patent suggests designs to correct or compensate for misalignment of the guide rails along which the two gliders travel. The two guide rails of Brauer are mounted separately in a vehicle door, and the compounding of manufacturing tolerances and assembly variability leads to lack of adequate parallelism of the two guide rails. Consequently, the Bauer patent suggests that only one glider (referred to as a mounting bracket by Bauer) be rigidly fixed to the windowpane while the other employs a mounting slot or eccentric cam to accommodate such misalignment. This design, however, can lead to reduced windowpane stability.
It is an object of the present invention to provide a cable regulator assembly having improved performance characteristics. It is a further object of the invention to provide a regulator assembly which provides good protection for the regulator cable along its travel path between the laterally spaced guide rails and is compatible with modern automotive design principles. Additional objects and features of the invention will become apparent from the following disclosure taken together with the detailed discussion of certain preferred embodiments.